KR101303606B1 - Apparatus for concentrating a nebulant - Google Patents

Abstract

Apparatus for concentrating a spray agent comprising a plurality of alternating spray stream tubes and corresponding reverse flow tubes in a spray flow tube and a reverse flow tube, or preferably in a stacked or coaxial arrangement, said spray flow tube and said reverse flow tube At least a portion of each form an opposite side of the gas penetrating tube. In use, the nebulizer communicates with the nebulizer stream, the nebulizer flow and reverse flow in the same or opposite direction, concentrating and disinfecting or disinfecting particles by concentrating the active ingredient, which is a drop of water, from 35 to 60 wt% hydrogen peroxide in water. do.

Hydrogen peroxide, concentrated, semipermeable membrane, flow tube, reverse flow tube, pervaporation

Description

Apparatus for concentrating a nebulant

The present invention relates to methods and apparatus for concentrating aerosols that can be used, for example, to disinfect or sterilize surfaces. The method and apparatus are particularly suitable for disinfecting or sterilizing medical devices, but are not limited to these uses.

This application is incorporated by reference in its entirety in pending applications AU2005904181, AU2005904196, and AU2005904198.

As a summary of these pending applications, sterilization processes and apparatuses that designate the following criteria are highly desirable.

(a) avoiding the need for vacuum

(b) avoiding the need for a rinse step

(c) avoiding the need for temperatures above 60 ° C;

Many prior art processes used vacuum and rinsing steps. They can increase complexity, increase the cost of the device, and significantly extend the time of a sterilization or disinfection processor (which means a lot of downtime for expensive medical devices). The use of high temperatures can damage many materials, more importantly, as well as increasing complexity and cost of disinfection equipment.

It would be desirable to provide a sterilization method and apparatus that meets this cryterrier and that achieves the most potent efficacy in pathogen destruction, particularly when treating blocked and overlapping lumen surfaces.

As the sterilization method, it is preferable to use hydrogen peroxide. Low concentrations of hydrogen peroxide are well known for their stability in transport, trade and disposal, and with little or no regulatory barriers to use. However, this method has a problem that a high concentration of hydrogen peroxide is required as a starting material. Industrial steam and plasma processors, for example, use 60% corrosive and irritating hydrogen peroxide solutions that require special packaging and handling precautions.

When hydrogen peroxide is used in the form of droplets (such as sprayed or ultrasonically sprayed), particles tend to accumulate on the surface as droplets and residual layers of hydrogen peroxide have potential problems. Medical devices, food packaging and other sterilized items need to be dried and stored to avoid recontamination. In particular, surgical instruments should not contain residual hydrogen peroxide at levels higher than 1 μg / cm 2.

However, it is very difficult to remove residual hydrogen peroxide. This is a related issue disclosed earlier in the Applicant's co-pending application with respect to the liquid system, which requires a cleaning that generates a long cycle of high temperature drying (to completely ignore any benefit arising from fast sterilization times and low processing temperatures), or catalase or It requires the use of other chemical means or the use of a vacuum device to decompose hydrogen peroxide (which creates a series of problems with the residual sulfide left in the equipment and still requires drying).

No discussion of the prior art through this specification should be construed as an admission that such prior art forms part of or is widely known in the art.

It is an object of the present invention to provide an improved method and apparatus for disinfecting or sterilizing a medical device that avoids or ameliorates at least some of the disadvantages of the prior art.

It is an object of preferred embodiments of the present invention to provide an improved method and apparatus capable of concentrating aerosols and improving their properties.

Throughout the specification and claims, terms such as 'comprises', 'comprising', etc., unless expressly required in the context, are meant to be inclusive, i.e. "included but not limited," as opposed to exclusive or exclusive meanings. Will be figured out.

According to the first aspect, the present invention provides a device for concentrating a spray agent.

Spray flow tubes; And

Including a backflow tube

At least a portion of the spray stream tube and the reverse flow tube each provide an apparatus for forming an opposite side of the gas permeation membrane.

According to a second aspect, the present invention provides a device for concentrating a spray agent,

A plurality of alternating spray stream tubes and corresponding reverse flow tubes,

At least a portion of each of the spray stream tubes and adjacent reverse flow tubes each forming an opposite side of the gas permeation membrane.

The alternating spray and reverse flow tubes may be of laminated construction. Or they may be coaxial tubular arrangements.

Each spray includes an inlet and an outlet. Each reverse flow tube includes an inlet and an outlet. Preferably the spray and reverse flows are in opposite directions. However, they may be in the same direction or in any other direction, for example vertical.

According to a third aspect of the invention, an apparatus for concentrating a spray agent is

Spray flow tubes; And

At least two reverse flow tubes,

At least a portion of the spray stream tube and the reverse flow tube each provide an apparatus for forming an opposite side of the gas permeation membrane.

According to a fourth aspect, the present invention provides a device for concentrating a spray agent,

At least two spray stream tubes; And

Including a backflow tube

At least a portion of the reverse flow pipe and the spray stream pipe each provide an apparatus for forming an opposite side of the gas permeation membrane.

According to the fifth aspect, the present invention provides a method for concentrating a spray agent,

(1) providing a spray stream containing the active ingredient in the solvent and having a first active ingredient: solvent ratio on the first side of the gas permeation membrane;

(2) increasing the first active component: solvent ratio on the first side to a second active component: solvent ratio greater than the first active component: solvent ratio by providing a reverse flow of gas to the second side of the gas permeation membrane; It provides a method to include.

Concentrated sprays are preferably used to sterilize and disinfect the particles.

The solvent is preferably water and the active ingredient is a biocide. Most preferably the biocide is hydrogen peroxide. The first active ingredient: solvent ratio is preferably about 30 wt%.

The second active ingredient: solvent ratio is preferably about 70 wt%. The reverse flow of gas is provided at a rate and time at which the second rate can no longer increase.

For reference, the gas is air and more preferably air with controlled humidity.

The semi-permeable structure or membrane is a woven or non-woven structure, or it may be a sheet or a membrane or a combination thereof and may be monolayer or multilayered.

The term “semi-permeable membrane” is used herein where the context includes all structures and membranes having the selected properties. The semipermeable membrane can be hydrophobic or hydrophilic in nature.

The semipermeable membrane is chosen such that the spray particles cannot penetrate first.

Where the context permits reference to transflective structures or membranes in this specification is not only those suitable for simple permeation, but also permits structures or membranes suitable for pervaporation and permits reference to permeation. Contains a reference to Other membranes than those disclosed may be used and may include membranes suitable for pervaporation.

In a very preferred embodiment hydrogen peroxide solution is sprayed with an initial concentration of at least 6%, preferably 20% to 35%, and more preferably 30 to 35%. Preferably the solution is sprayed in an ultrasonic atomizer operated at 2.4 MHz to produce an aerosol in which particles with a size range distribution of about 1 to 10 microns are suspended in the air stream. As used herein, the term "spray" refers to liquid droplets (ie, finely divided liquid particles) that accompany the gas stream. The system of liquid droplets entrained or suspended in gas is an "aerosol".

Without wishing to be bound by theory, it is believed that if water vapor permeates the membrane, the water evaporates from the spray droplets to store the equilibrium vapor pressure in the spray stream. Continued evaporation from the water droplets results in a hydrogen peroxide solution that is more concentrated in the spray and smaller in size.

 These small, concentrated spray particles are more effective as fungicides than the prior art hydrogen peroxide vapor and are more effective than the prior art hydrogen peroxide atomizer disinfectants and treatments because high concentrations of fungicide can be obtained per unit volume.

The penetration of air into the spray stream is sterilized by the membrane not being penetrated by the microorganisms.

According to a sixth aspect, the invention is selected such that in the treatment according to any of the preceding aspects the semipermeable membrane removes one or more vapors by treatment of pervaporation.

Although the present invention has been described herein with reference to hydrogen peroxide as a biocide, the present invention dissolves in the case where the biocide is another hydrogen peroxide or peroxy compound, or in other known vaporizable biocides or suitable solvents (not necessarily aqueous). In the case of biocides, the same applies. It is also highly desirable to inject the biocide as an aerosol, but in less preferred embodiments the biocide can be injected as a vapor and the vapor is then at atmospheric pressure by the external flow of air (or other fluid) adjacent to the outer membrane. Removed. Injection of biocide with aerosol is highly desirable because the initial density of biocide per liter of container can be achieved higher than vapor. Applicant's pending application indicates that an aerosol believed to be similar or identical to the aerosol produced in the process according to the present invention is more effective than vapor.

According to the seventh aspect, the present invention provides a method for sterilizing and disinfecting a particle or a part of a particle.

(1) closing the particles or particle portions within the first container having at least a portion of the semi-permeable or membrane wall;

(2) the semipermeable structure or membrane is selected to allow steam to pass from the inside of the container to the outside while providing a barrier to the ingress of microorganisms and the release of atomizer particles;

(3) receiving a biocide solution containing a biocide dissolved in a solvent in a second container;

(4) concentrating the biocide in the second container by removing the solvent to form a concentrated biocide; And

(5) introducing a concentrated biocide from the second container into the first container as a liquid or vapor or a combination thereof;

Steps (4) to (5) provide a method carried out above atmospheric pressure.

In a preferred embodiment according to the sixth aspect, the aqueous hydrogen peroxide solution is concentrated with a spray in the chamber by first removing the water passing through the membrane at atmospheric pressure, for example for a concentration of 35%. The concentrated spray is then housed in another chamber, preferably a bag or container, having a semipermeable membrane forming a portion or wall to be sealed. This allows the particles to be sterilized and stored in the second container and to remove residual hydrogen peroxide and water. Preferably the present invention provides nanosprays with 90% of the particles, particularly in the range of 3 to 5 μm, hydrogen peroxide concentrations of> 70 wt% and water concentrations less than 30 wt%.

According to an eighth aspect, there is a nanospray comprising a solution of hydrogen peroxide in which the liquid particles are suspended in finely divided forms having a concentration greater than 60 wt% of hydrogen peroxide and having an average diameter of less than 1.0 micron. Preferably the water droplets have an average diameter of less than 0.8 microns.

In the prior art aerosol systems, the hydrogen peroxide liquid particles will be recognized as having a concentration of less than 35 wt% of hydrogen peroxide and an average diameter of more than 2 microns. For aerosols, the relationship between particle size and drop rate is nonlinear, and a small decrease in particle diameter not only increases the overall surface area of the gas / liquid system surface, but also greatly increases suspension stability.

Preferably, the spray according to the seventh aspect has a hydrogen peroxide density (grams of hydrogen peroxide / aerosol) that is greater than the hydrogen peroxide density of the steam below the saturation limit at the corresponding temperature and humidity.

1 is a reconstruction of the drawing of US 4,797,255 showing how the boiling point of a water / hydrogen peroxide mixture changes with concentration at atmospheric pressure (curve A) and how the gas composition changes (curve B).

2 is a diagram of a first simple embodiment of the present invention.

3 is a view of a sterilizer showing a preconcentrator of the present invention.

Figure 4 is a more detailed schematic view of the sterilizer showing the preconcentrator of the present invention.

5 shows another embodiment of the present invention.

Figure 6 shows the flow pattern and reverse flow of the spray agent of the embodiment of the present invention.

7 shows a plate that can be used to separate a semipermeable membrane in an embodiment of the present invention using a stacked arrangement.

8 shows the results from the membrane thickener of the present invention.

9 shows an ultrasonic probe for sterilizing an array with a nebulizer of the present invention.

Description of the Related Art [0002]

1: Item to be sterilized 2: sterilization chamber

3: semi-permeable membrane 4: pre-concentrator chamber

5: valve 6: ultrasonic nebulizer

The present invention will be described in terms of sterilization, but it will be understood that the preconcentrator and preconcentration method of the present invention can be used in various fields where concentrated sprays are required, namely, drug delivery, painting / printing, food preparation, material preparation, and the like. Can be. For example, all treatments are disclosed including concentration of the hydrogen peroxide solution, preferably by reducing the pressure to evaporate the water and removal of the water through the vacuum pump prior to evaporating the solution.

A general preconcentration process of the present invention is described below and can be seen with reference to FIG. 3. The article 1 to be sterilized is arranged in a sterilization chamber 2. The sterilization chamber 2 may be a suitable container but is preferably a bag made of a semipermeable membrane or a sealed container having a window of the semipermeable membrane 3.

The preconcentrator chamber 4 of the present invention is connected upstream of the sterilization chamber 2. The sterilization chamber 2 and the preconcentrator 4 are connected so that the flow between the preconcentrator and the sterilization chamber can be opened or closed by the valve 5.

The ultrasonic atomizer 6 is connected upstream of the preconcentrator chamber. Preferably, hydrogen peroxide solution with an initial concentration of about 30-35% is sprayed in the ultrasonic nebulizer.

The nebulizer 6 is supplied with sterilizing solution continuously or intermittently from a large source 7 while maintaining a predetermined liquid level of the nebulizer or a single shot dosing system, for example one or more sterilizations. Cartridges may be provided that provide sufficient solution during the cycle. Alternatively, a prepackaged sterile solution may be provided in a capsule placed in a suitable nebulizer so that the capsule can be contacted with the ultrasonic transducer of the nebulizer. In this case, a means is provided for opening the capsule to release the solution with a spray. In another embodiment, a sterilizing solution may be provided in a capsule having an ultrasonic transducer as a component suitable for being activated through contact extending through the capsule wall when the capsule is inserted into the nebulizer.

The nebulizer 6 need not be an ultrasonic means and other means for forming an aerosol including sprays, jets and other devices may be used. It can be envisioned that hydrogen peroxide can be prepackaged and stored as an aerosol in an aerosol container and can be received from an aerosol container. It can also be appreciated that cassettes incorporating an ultrasonic transducer can be used to generate in situ error rosols in a closed container that provides an electrical connection to the outside providing activity and control.

The nebulizer 6 is preferably operated at about 2.4 MHz to form an aerosol (“microparticles”) in which at least 90% of the droplets are generally between 1 and 10 μm in diameter and have a medium size of 3 to 5 μm in diameter.

Although the present invention is disclosed with reference to spraying by an ultrasonic nebulizer, it will be understood that other means for spraying, including sprays, jet nebulizers, piezoelectric nebulizers, and the like, may be used. As disclosed in the co-pending application of the applicant (PCT / AU99 / 00505), when ultrasonic spraying is used, small particles can be obtained by containing a surfactant, eg alcohol, in the sterilizing solution. A continuously operated ultrasonic nebulizer is not necessary and in a preferred embodiment of the present invention the nebulizer is switched on and off, for example, at periodic intervals (or at irregular intervals) which are operated for approximately 20 seconds per minute.

The spray of aerosol or microparticles is then propelled into the preconcentrator 4 by a fan 8 upstream of the sprayer 6. The microparticles formed by the nebulizer 6 are incorporated into a gas stream which is air in the preferred embodiment. Not requiring the supply of filtered sterilizing air is an important advantage of the preferred embodiment of the present invention over the prior art. Instead, the present invention can remove unsterilized air from the sterilization chamber and sterilize it while recycling it in use. However, if desired, sterile filtered air may be used. The gas flow does not necessarily need to be air, but may be, for example, an inert gas such as nitrogen or argon or oxygen or ozone.

In other words, the preconcentrator 4 is operated by exposing aerosol droplets to one side 10 of the semipermeable membrane 9 while the airflow moves the other side 11 of the semipermeable membrane. This selectively evaporates the water from the aerosol droplets and concentrates them more against hydrogen peroxide. As a result of the selective evaporation of water, the aerosol droplets in the preconcentrator 4 are more concentrated for hydrogen peroxide at concentrations up to 60% or more. After hydrogen peroxide and water have been evaporated to equilibrium fixed ratios, the water continues to evaporate selectively from the water droplets until the hydrogen peroxide concentration is at its maximum.

Once formed, small high concentrations of water droplets come into contact with the particles to be sterilized.

There are two possible preferred modes of operation of the preconcentrator.

In the first mode of operation, which is a batch concentration process, the aerosol of 35% hydrogen peroxide solution with a droplet size of 1 to 10 μm is closed and the path between the concentrator 4 and the sterilization chamber 2 is closed. Leads to). The preconcentrator chamber is then separated (by closing both valves 5 and 12) and the aerosol in the preconcentrator 4 is concentrated. Concentration in the preconcentrator occurs beyond the evaporation of hydrogen peroxide and water at equilibrium fixed ratios until the maximum concentration of hydrogen peroxide is achieved. When this maximum concentration is achieved, the path between the preconcentrator and the sterilization chamber is opened by opening the valve 5 and the concentrated spray agent is introduced into the sterilization chamber 2.

In a second alternative mode of operation, which is a continuous concentration process, the path between the preconcentrator 4 and the sterilization chamber 2 is left open. An aerosol of 35% hydrogen peroxide solution with a droplet size of 1 to 10 μm enters the preconcentration chamber 4 and continues to pass through the preconcentrator with the propulsion of the fan 8. As the aerosol droplets pass the preconcentrator 4, the water is selectively removed. The remaining time of water droplets in the preconcentrator is such that the maximum possible concentration of hydrogen peroxide is achieved by the time the water droplets exit the preconcentrator.

Sprays can be, for example, on / 18 seconds off for 2 seconds for a 2 minute cycle; Or it can be continuously or intermittently introduced to the preconcentrator 4 with on / off for 5 seconds.

However, although a batch mode (a) or a continuous mode (b) is used, or a combination of continuous or batch modes is used, the aerosol droplets exiting the preconcentrator 4 and entering the sterilization chamber 2 are made at maximum. Hydrogen peroxide concentration.

As the concentration of hydrogen peroxide in the droplets increases, the proportion of hydrogen peroxide in the vapor increases in equilibrium with the droplets.

When the concentrated spray is introduced into the sterilization chamber 2, it contacts the particles to be sterilized (1) and acts on the pathogens on the surface. The sterilization chamber 2 is sealed from the preconcentrator 4. Since the concentration of hydrogen peroxide is maximum, no further concentration of the hydrogen peroxide solution occurs in the sterilization chamber (2). Any evaporation of the sterilization chamber occurs such that hydrogen peroxide and water evaporate at a fixed equilibrium ratio. The concentrated biocide is then contacted with the particles to be sterilized. The particles to be sterilized can be stored in the sterilization chamber until needed. It also allows the removal of residual hydrogen peroxide and water.

Referring to FIG. 4 to illustrate each step, the cycle initiates spraying of 27 to 35% hydrogen peroxide into the microwater droplets inside the spray chamber 6 using an ultrasonic piezoceramic transducer vibrating at 2.4 MHz. The transducer is operated according to a suitable cycle such that it is continuous or the spray is intermittent. Spray mist has microdroplets with the same composition as the bulk solution from which it is derived.

Once produced, the spray mist is transported by the blower fan 8 to the membrane concentration system 4 where it is concentrated to submicron particles or nanospray by evaporation.

The membrane concentrator 4 is preferably a multilayer apparatus in which a spray agent flows to the membrane layer having a different air flow on the other side. Selective removal of the water vapor ratio from the spray occurs in the membrane thickener due to the different partial pressures of water and hydrogen peroxide. The concentrator will be heated electrically if required to provide the desired effect. The water droplets are not only concentrated (60-70%) but also smaller due to the loss of solvent (water). Droplets also increase surface area / volume and become more stable. The end result is a very fine, stable, concentrated mist or nanospray. At the outlet of the concentrator, the mist is finally concentrated so that the concentration of hydrogen peroxide in the sterilization chamber no longer occurs in the sterilization chamber.

In the simple embodiment shown in FIG. 2, the membrane concentrator is a stackable assembly of modules consisting of four main components, a flow bed, an end plate, a connecting rod and a membrane sheet. 5 shows a preferred stack of enrichment modules.

The flow layers 10, 11 are formed of thin rectangular or rectangular plates 12 with a large open area inside and four slots (galleries) parallel to the outer edge, two of which are internal through the slots. Connected to the space. The direction of the flow layers determines the number of floors common to any particular gallery (if a rectangular portion is used) and thus two different flow lines drive one single assembly through the assembly's method.

The end plate 13 connects the outer tube or device to the membrane assembly and each end plate has two connection points corresponding to two gallery slots. The slots in these end plates form a manifold that directs flow for a particular gallery per connection and the connections are offset by 90 degrees to access different galleries.

If the five flow layers are stacked on top of one another, for example alternately deflected, i.e. 90 degrees from each other and separated by sheets of membrane material, they have two flow layers 15 on one side and the other on the other side. Two groups of flow layers are formed with three separate flow layers 16 in the block. This flow layer is assigned to the nanospray (15 in this case) or crossflow / reverse flow (16 in this case) connection and control of the spraying is possible by adjusting the flow rate.

Any design can be used so that the blocks match each other in a properly sealed arrangement, but the connecting rod is used to compress the layer between the end plates and to create a vapor seal. The membrane material 9 also acts as a gasket between the layers.

While the vapor pressure of hydrogen peroxide at ambient temperature can be neglected and the water is selectively evaporated in the membrane concentrator, as a precaution against the hydrogen peroxide flow leaving the system, the reverse flow is transferred directly to the catalytically destructive device.

The semipermeable membrane 9 in this embodiment is preferably made of KIMGUARD ^™ , which is a three-layer non-lint thin plate structure that uses polypropylene and has a hydrophobic inner layer and is resistant to bacterial penetration. The two outer layers provide corrosion resistance and strength. Because of its multi-layer structure, it does not actually have a small pore size but can be penetrated by very small channels that provide a tortuous path that limits the passage of particles that are less than 0.2 microns, ie microorganisms below 0.2 microns cannot penetrate. . This structure allows water and hydrogen peroxide vapor to penetrate through the channel of the structure. The channels do not allow the passage of bacteria into the chamber and do not allow the spray to pass through. Kimguard has a hydrogen peroxide repulsion of 3.8 KPa (measure hydrophobicity) and a cross-dimensional tensile load of 70 newtons and a machine-directional tensile load of 130 newtons.

The semipermeable membrane 9 may be another suitable semipermeable membrane that facilitates the removal of water without being able to penetrate by microorganisms and spray particles. Other structures and membranes that can be penetrated by water vapor and hydrogen peroxide vapor and not by bacteria can be, for example, TYVEX ^™ and SPUNGUARD ^™ (but KIMGUARD ^™ is TYVEX ^™ under the conditions used herein). It has been found that it can penetrate 2-3 times more hydrogen peroxide). As discussed below, other semipermeable membrane materials such as NAFION ^™ (which are hydrophilic) and the like can also be used.

NAFION ^™ is an interpolymer of tetrafluoroethylene and perfluoro 3, 6, dioxa-4-methyl-octin-sulfonic acid. These materials are hydrophilic and have very high moisture of hydration. NAFION ^™ can be absorbed 22% by weight of water. In this variant, absorption proceeds to the primary kinetic reaction. The water molecules pass through the membrane and then evaporate into ambient air until equilibrium with the external humidity reaches a continuous process called pervaporation. The external flow of air to the outside of the membrane provides rapid removal of moisture from the external surface and promotes pervaporation. Unlike simple permeation, where molecules are simply diffused through open pores, in pervaporation the membrane is active in selectively attracting molecules from one side of the membrane to the other and can do so at a differential rate for other types of chemical molecules.

In this embodiment, the bactericide described above is a hydrogen peroxide solution as 35% aqueous solution acting as a solvent. Water is a preferred solvent for use with hydrogen peroxide. Water boils at 100 ° C and hydrogen peroxide boils at 151 ° C at atmospheric pressure. Hydrogen peroxide boils at 151.4 ° C. at 760 mm. 1 of US Pat. No. 4,797,255 shows how the boiling point at atmospheric pressure of a water / hydrogen peroxide mixture changes with concentration (curve A) and shows how the gas composition changes (curve B). As can be seen pure water boils at 100 ° C. at atmospheric pressure. It is evident from FIG. 1 that the concentration of hydrogen peroxide in steam below 100 ° C. can be neglected at atmospheric pressure. The solvent may be, for example, an aqueous or non-aqueous alcohol selected in combination with the fungicide to be used. Adding water to ethyl alcohol results in an azeotrope that lowers the boiling point of the solvent, causing the water to evaporate suddenly at low temperatures, which would otherwise be possible. The addition of another azeotrope will be equally beneficial. It is within the scope of the present invention to use azeotropic mixtures that facilitate the removal of solvent from spray solution particles. It may be contemplated that a nonaqueous solvent or a combination of suitable solvents may be used for any biocide.

In the case of hydrogen peroxide, the sudden evaporation of water increases the concentration of the fungicide. If 35% hydrogen peroxide solution is used in the present invention, the microspray agent will have a concentration of, for example, 60 to 80% after the heating and steam removal step. This has the advantage that the starting material can be treated relatively safely with the advantage that it is no longer necessary to generate a concentration during the treatment and then to treat the hydrogen peroxide. In addition, the average particle size is greatly reduced and in preferred embodiments the microspray particles have an average diameter of less than 1 micron and more preferably less than 0.1 micron. The small particle size results in a very stable suspension with negligible sedimentation and a very high concentration of liquid disinfectant per liter of spray which provides a significant increase in the liquid / gas interface. The inventors believe there is a high concentration of hydrogen peroxide molecules in terms of gas / liquid systems in these nanoparticles that occur in the microparticles. Solutions of concentrations lower than or higher than 35% can be used as starting materials and good results can be obtained with 40% solution as well as with 1% or 3% hydrogen peroxide solution, but by matching or blocking the surface to obtain satisfactory results. The time to achieve is less than optimal with hydrogen peroxide concentration below 30%, and controlling the problem is good for concentrations below 35%. The preferred embodiment disclosed uses an aqueous solution of hydrogen peroxide as a bactericide, but other hydrogen peroxide and peroxy compound solutions as well as peroxy complex solutions (including non-aqueous complexes in organic solvents) can be used. Fungicides other than hydrogen peroxide can be used in the present invention with the choice of suitable solvents including, without limitation, halo compounds, phenolic compounds, halogen phenolic compounds and other known biocides.

While the concentration of hydrogen peroxide in water droplets produced from 30 to 35% hydrogen peroxide solution generally reaches 60% or more, it is not necessary to achieve this high concentration of hydrogen peroxide. For example, in another preferred embodiment, the starting solution having a concentration of 10-15% hydrogen peroxide is sprayed and concentrated with approximately 45-60% hydrogen peroxide. Any starting concentration of hydrogen peroxide can be used and concentrated to the theoretical maximum level that can be achieved under the prevailing conditions of relative humidity and temperature. Generally, the concentration of hydrogen peroxide of 10 to 15% to 30 to 35% is concentrated to 45 to 60% or more in the spraying agent used as the starting solution.

In embodiments where the particles to be sterilized are part of an ultrasonic probe 20, for example a type of probe that can be inserted into a community for diagnostic purposes, the portion of the probe 20 to be treated is the chamber 2. (It is the same as the example of FIG. 9). In this case, the chamber is in particular a chamber of a particular shape designed so that the entire particle does not need to be in the chamber and only a part of the probe to be treated is embedded. The probe can be suspended inside the chamber by sealing around the plug where the power cord enters the probe.

The nanospray is then delivered to a chamber 2 that is applied to the target surface. An ultrasound device may be inserted into the chamber through a panel of the device. One possible inlet is maintained from the top surface through the threaded top cover through which the cord of the device can be clamped and in the position where it is inserted into the chamber. The passage of the nanospray from the concentrator to the chamber is controlled by a check valve (5). The check valves 5, 12 can control whether the devices will be operated in a batch, continuously or a combination thereof.

If the apparatus is operated in batches, the valve 5 is opened at the appropriate time after the concentration has occurred.

If the device is operated continuously, the valve remains open with the remaining time and flow rate of the spray to be adjusted before it is maximized as it exits the chamber.

In general, the chamber 2 is made of a thermally conductive material such as stainless steel or aluminum. Various coatings, such as teflon, can be used inside the chamber to reduce the risk of breakage of hydrogen peroxide. The sterilization chamber is electrically heated using heat trace wiring used on the conductive metal surface. Or additionally heated air may be blown into the chamber. The chamber atmosphere that supplies the blower air consists of a combination of other chambers on the opposite side of the chamber for inflow. The chamber is separated from the production and recirculation circuit by the combining valves when the nanospray cycle is complete (approximately 1-1.5 minutes). This separation from adjacent circuits is called a "stop time" or more generally a "hold" time.

The surface of the object 1 to be treated with the spray agent is exposed to the nanospray particles for a time sufficient to sterilize the surface. Surprisingly, nanoatomizers have been found to have a faster effect than prior art aerosols and are more effective in penetrating overlapping surfaces and treating closed surfaces that are not directly unexposed. The reason for this is not clear, but the very high density of the nanospray (e.g. higher at 2.0 mg / L or 40% RH) is spread through the space of the sterilization chamber and at the same time does not actually condense or hardly condense on the surface. will be. Nanospray particles have a larger surface area in the gas / liquid system than original microspray particles and are very small in diameter and consequently stop for a very long period of time. Without wishing to be bound by theory, the Applicant believes that nanoparticles collide on the surface at larger periods than prior art microparticles and have a longer residual time on the surface than vapor molecules. Compared with the prior art aerosol treatment, the surface treated by the present invention can be dried rapidly and relatively uncontaminated by residual hydrogen peroxide. When treating lumens the lumens are preferably connected to recognize the flow of spray through the lumens. Preferably the outer and overlapping surfaces may also be exposed to the spray in the chamber or cassette.

The chamber 2 may be formed entirely of a semipermeable membrane or structure, or at least a part thereof may have a wall that is a semipermeable membrane or a structure of a shape and design suitable for the needs of the treatments disclosed herein and in any way by the microorganisms. It can be sealed so that it cannot penetrate. Other semipermeable membranes or structures can be selected based on the suggestions provided herein. The container may be permanently connected to the nebulizer circuit or may or may not be connected by tube and plug connection by suitable connectors or other means.

Once the down time is complete (approximately 1 to 2 minutes), the system will go into catalytic destruction mode or simply “empty”. In this cycle, a suction fan for regulating (opening under pressure) a check valve connected to the chamber is engaged and the other valve allows fresh air to enter the chamber at a controlled rate. This cycle moves the nanospray into catalytic destruction mode and the catalyst is used to convert hydrogen peroxide into harmless water vapor and oxygen. The catalytic breaker module consists of a metal oxide which is a ceramic honeycomb layer baked through a similarly treated ceramic dictation packaged in a suitable container. The amount of catalyst is proportional to the amount of hydrogen gas extracted from the chamber as well as the flow rate from the chamber. This cycle takes approximately one minute to complete and upon completion the chamber can be accessed to recover the sterilized target device. In this configuration, the total cycle time for high levels of sterilization is approximately 5 minutes or less. It is understood that the time for sterilization is very cumbersome and takes a long time.

In a preferred embodiment, the droplet density in the aerosol passing from the preconcentrator through the sterilization chamber can be measured by passing an infrared beam through the connecting conduit of the meter and measuring the beam attenuation. This gives a measure of the amount of hydrogen peroxide solution per unit time entering the sterilization chamber, varying with the odrosol droplet density. Infrared is preferably a frequency which is not absorbed by hydrogen peroxide per second and therefore does not record hydrogen peroxide even if diarrhea. Knowledge of aerosol density, temperature and residence time can prove the results if necessary.

The preconcentrator can be operated in such a way that it will always output a spray containing hydrogen peroxide at a predetermined theoretical maximum concentration and thereby avoid the need to determine the concentration of hydrogen peroxide at any point in the sterilization treatment.

Concrete example

8 shows the results of concentration of hydrogen peroxide using the membrane thickener of the present invention. FIG. 8 compares the% relative humidity (RH) and hydrogen peroxide (H ₂ O ₂ ) levels (ppm) measured in a 3 liter chamber with the aerosol flow rate at 9 L / min to the membrane thickener described above or bypassing it all. do. The starting concentration of hydrogen peroxide is 30%. Similar membranes are obtained with NAFION and TYVEK, but the membrane used in this case is KIMGUARD.

Bypassing the membrane thickener / module showed a relative humidity of 46% and a hydrogen peroxide level of about 980 ppm (FIG. 8A).

However, when a membrane thickener is used, the corresponding concentration of hydrogen peroxide is higher than 2100 and the relative humidity drops to 28%. In fact, the use of the preconcentrator of the present invention removes large amounts of water, doubling the hydrogen peroxide concentration.

Tables 1, 2 and 3 below show that the increase in reverse flow increases the concentration of hydrogen peroxide in a 3-liter chamber over a 5-minute period with NAFION, the maximum effect.

Table 1: Effect of inverse flow rate in NAFION membrane module on the ratio between hydrogen peroxide and water by weight in a sterilization chamber at 50 ° C

Conditions of Spray / Nano Spray Supply Reverse Flow Rate L / min Ratio of H ₂ O ₂ / H ₂ O Bypass Thickener N / A 0.033 Pass through thickener 0.0 0.061 4.5 0.108 7.5 0.118 9.0 0.088 12.0 0.102

Table 2: Effect of inverse flow rate in TYVEK membrane module on the ratio between hydrogen peroxide and water by weight in a sterilization chamber at 50 ° C

Conditions of Spray / Nano Spray Supply Reverse Flow Rate L / min Ratio of H ₂ O ₂ / H ₂ O Bypass Thickener N / A 0.033 Pass through thickener 0.0 0.046 4.5 0.083 7.5 0.082 9.0 0.080 12.0 0.58

Table 3: Effect of inverse flow rate on the KIMGUARD membrane module on the ratio between hydrogen peroxide and water by weight in a sterilization chamber at 50 ° C

Conditions of Spray / Nano Spray Supply Reverse Flow Rate L / min Ratio of H ₂ O ₂ / H ₂ O Bypass Thickener N / A 0.053 Pass through thickener 0.0 0.063 4.5 0.112 7.5 0.149 9.0 0.125 12.0 0.109

Table 4 below shows the effects of nanospray treatment using membrane thickeners of carriers injected with 5 × 10 ⁶ cfu B. stereo thermophilus / carrier at 400 ppm of hard water and 5% horse serum. The flow rate of the aerosol is 9L / min, the reverse flow is 9L / min, the temperature in the chamber is 50 ° C, and the starting concentration of hydrogen peroxide is 30%. The hydrogen peroxide delivered is 0.11 g / L.

Table 4: Relation of time to seed reduction under different surface conditions

cfu / carrier Exposure time (min) Porcelain penicillin cylinder (log reduction)
n = 50 Stainless steel
Washer (log reduction)
n = 10 Overlapping stainless steel washers 85 mm2 (log reduction)
n = 3 5 × 10 ⁶ One 2.6 5.9 2.1 5 × 10 ⁶ 2 5.8 〉 6 4.3 5 × 10 ⁶ 5 〉 6 〉 6 5.2 5 × 10 ⁶ 10 〉 6 〉 6 〉 6

The following describes the particle size types that can be obtained by the preconcentrator of the present invention. Table 5 shows the particle size distribution of the spray from the ultrasonic nebulizer fed with 30% hydrogen peroxide solution at various temperatures.

Table 5

Output T of heater
℃ Below 10%
(Particle size, μm) 50% below
(Particle size, μm) Below 90%
(Particle size, μm) 25 2.84 5.5 9.48 55 0.95 1.36 2.0 60 0.58 0.86 1.36

Table 6 shows the particle size data at 25 ° C. of the spray when the NAFION membrane is used for various airflows on the outside.

Table 6

Reverse flow ㎧ Below 10%
(Particle size, μm) 50% below
(Particle size, μm) Below 90%
(Particle size, μm) 0 2.29 4.61 8.58 3.2 2.33 3.99 6.36 7.5 2.0 2.9 3.96

Table 7 shows the particle size data of the spray at 25 ° C. when the KIMGUARD membrane is used as air flow rate in various flows on the outside.

Table 7

Reverse flow ㎧ Below 10%
(Particle size, μm) 50% below
(Particle size, μm) Below 90%
(Particle size, μm) 0 2.29 4.61 8.58 3.2 2.31 4.17 7.2 7.5 2.57 4.2 6.51

The particle size is about half of NAFION (corresponding to a drop of water droplets of about 30% of its original size) and in the case of KIMGUARD (corresponding to water droplets of about 13% of its original size). It seems to have fallen by about one third.

Although the present invention has been described herein with reference to hydrogen peroxide as a fungicide, the present invention may use other hydrogen peroxide, peroxy compounds or compounds thereof. Other classes of biocides can be used including, without limitation, halogenated biocides, phenolic biocides, and quaternary biocides, with the advantage of using solvents other than water. Similarly, although the present invention has been primarily described herein with reference to a starting solution having 35% hydrogen peroxide, other starting concentrations may be used if concentrations between about 20% and 35% are desired.

The principle suggested here can be used to concentrate hydrogen peroxide by steam or permeate steam treatment by penetrating the membrane without requiring pressure reduction. However, if the sterilization is ineffective, there is no effect of using the aerosol of the invention (as described in the applicant's pending application).

Claims (35)

In the apparatus for concentrating a spray agent Spray flow tubes; And Including a backflow tube And at least a portion of said spray stream tube and said reverse flow tube each forming an opposite side of a gas permeation membrane. The apparatus of claim 1 further comprising a nebulizer connected to the nebulizer flow tube. The apparatus of claim 1 further comprising humidity control means for controlling the humidity of the reverse flow entering the reverse flow tube. 4. The method according to any one of claims 1 to 3, A plurality of alternating spray stream tubes and corresponding reverse flow tubes, At least a portion of each of the spray stream tubes and adjacent reverse flow tubes each forming an opposite side of the gas permeation membrane. 5. The apparatus of claim 4 wherein the alternating spray stream tubes and the reverse flow tubes are in a stacked configuration. 5. The apparatus of claim 4, wherein the alternating spray stream tubes are coaxially coplanar arrangements. The device of claim 1, wherein the device for concentrating the spraying agent is Spray flow tubes; And At least two reverse flow tubes, And at least a portion of said spray stream tube and said reverse flow tube each forming an opposite side of a gas permeation membrane. The device of claim 1, wherein the device for concentrating the spraying agent is At least two spray stream tubes; And Including a backflow tube And at least a portion of said reverse flow pipe and said spray stream pipe respectively define opposite sides of said gas permeable membrane. 4. The spray according to any one of claims 1 to 3, wherein each spray flow tube comprises an inlet and an outlet, and each reverse flow tube comprises an inlet and an outlet, and the spray flow and reverse flow are the same or opposite. Direction device. 4. The apparatus of any one of claims 1 to 3, wherein each spray stream tube comprises an inlet and an outlet and the reverse flow tube is directed in a reverse flow direction relative to the spray flow direction. In the method of concentrating a solution having a first ratio of the active ingredient to the solvent as a solution containing the active ingredient in the solvent, (1) spraying a solution to form a spray with a droplet of which the concentration of the active ingredient is the first ratio of the active ingredient to the solvent (2) providing a flow of spray to the first side of the gas permeable membrane; And (3) by providing a reverse flow of gas to the second side of the gas permeable membrane, the second ratio of the active ingredient to the solvent is greater than the first ratio of the active ingredient to the solvent on the first side. Increasing in proportion. In the method of concentrating a spray agent, (1) providing a stream of spray comprising the active ingredient in the solvent and having a first ratio of active ingredient to solvent on the first side of the gas permeable membrane (2) by providing a reverse flow of gas to the second side of the gas permeable membrane, the second ratio of the active ingredient to the solvent being greater than the first ratio of the active ingredient to the solvent on the first side; Increasing in proportion. 13. The method of claim 11 or 12, wherein the active ingredient is a biocide and the concentrated spray is used to sterilize and disinfect the article. The method of claim 11 or 12, wherein the solvent is water. The method according to claim 11 or 12, wherein the active ingredient is selected from hydrogen peroxide or a peroxide compound. 13. The method of claim 11 or 12, wherein the first ratio of active ingredient to solvent is below 35 wt%. The method of claim 11 or 12, wherein the second ratio of active ingredient to solvent is greater than 64 wt%. 13. The method of claim 11 or 12, wherein the reverse flow of gas is provided at a rate and time such that the second ratio of active ingredient to solvent will reach an equilibrium ratio no longer increased. 13. The method of claim 11 or 12, wherein the gas is air or air with controlled humidity. The method according to claim 11 or 12, wherein the transflective structure or membrane is a woven or unwoven structure, a sheet or a film or a combination thereof, and is a single layer or a multilayer structure. The method of claim 11 or 12, wherein the semipermeable membrane is hydrophobic. 13. The method of claim 11 or 12, wherein the semipermeable membrane is selected to prevent first penetration of the atomizer particles at the first ratio of active ingredient to solvent. delete 13. The method of claim 11 or 12, wherein the spray agent is an aqueous hydrogen peroxide solution having an initial concentration from 6% to 35wt% hydrogen peroxide. 13. The method of claim 11 or 12, wherein the solution is sprayed in an ultrasonic atomizer operated greater than 2.0 MHz and particles having a size range distribution of 1 to 10 microns are suspended in the air stream. 13. The method of claim 11 or 12, wherein the semipermeable membrane is selected to remove one or more vapors by pervaporation treatment. A method for disinfecting or sterilizing an article comprising contacting the biocide solution concentrated by the method according to claim 11 or 12 with a spray or vapor. In the method for disinfecting or sterilizing particles, (1) evaporating the solution having the first ratio of the active ingredient to the solvent as a solution containing the active ingredient in the solvent; (2) providing a stream of steam to the first side of the gas permeable membrane; (3) by providing a reverse flow of gas to the second side of the gas permeable membrane, the second ratio of the active ingredient to the solvent is greater than the first ratio of the active ingredient to the solvent on the first side. Increasing in proportion; And (4) causing the vapor from step (2) to contact the particles for a time sufficient to sterilize or disinfect. The method of claim 28, wherein the method is carried out above atmospheric pressure. 29. The method of claim 28, wherein the reverse flow of gas is provided at a rate and time such that a second ratio of active ingredient to solvent is reached at which no further increase is achieved. A method for disinfecting or sterilizing an article or part of an article, the method comprising: (1) closing the particles or particle portions within the first container having at least a portion of the semi-permeable or membrane wall; (2) the semipermeable structure or membrane is selected to allow steam to pass from the inside of the container to the outside while providing a barrier to the ingress of microorganisms and the release of atomizer particles; (3) receiving a biocide solution containing a biocide dissolved in a solvent in a second container; (4) concentrating the biocide in the second container by removing the solvent to form a concentrated biocide; And (5) introducing a concentrated biocide from the second container into the first container as a liquid or vapor or a combination thereof; Steps (4) to (5) are carried out above atmospheric pressure. The method according to claim 31, wherein the step of concentrating is the method according to claim 11. 32. The method of claim 31 wherein the first container membrane cannot be penetrated by the microorganisms and the particles are sterilized and stored in the first container. 32. The method of claim 31, wherein the nebulizer at the first ratio has 90% of the particles in the range of 3 to 5 microns. 32. The method of claim 31, wherein the spraying agent at the second ratio has an average particle size of less than 1.0 micron.

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